A method for shock-resistant packaging of a product and a plane cardboard blank for carrying out the method.
The present invention relates to a method for shock-resistant packaging of a product in an essentially box-shaped cardboard packing comprising the steps of local application of an adhesive layer to a base surface of the cardboard packing, bringing the product into contact with the adhesive layer and closing the packing.
For a number of different products which during transport and handling should be protected against mechanical damage in the form of impact loads, it is well-known to provide a shock-resistant packaging in a box-shaped cardboard packing permitting a piled and organized transport and storage, also for products which per se have a somewhat irregular form.
In conventional packaging of this kind, an inner packing usually corresponding to the inner shape of the cardboard packing is used in the form of shells or blocks from a workable material, in particular foamed plastics such as polystyrene, because such shells and blocks can be shaped to fit the outer contour of the packed product. The product is thus situated securely in the cardboard packing, and a good mechanical protection is hereby obtained. However, this form of packaging has the inconvenience that due to the use of particularly shaped inner packing elements, it is relatively expensive and, at the same time, rather time-consuming as both packaging and unpacking of the product must as a rule be carried out manually. The storage of the inner packing implies a larger need for storage yard, and the disposal of the inner packing after use entails expenses and an increased environmental impact.
From U.S. Pat. No. 3,891,090 it is known to pack various form of products, especially those of a minor size in a box-shaped cardboard packing in which a tubular inner packing element of heat-shrinkable plastic film is adhesively affixed to a base surface. Upon arrangement of the product in this inner packing element, the heat shrinkable tube is upon application of heat made to tightly encompass the product. However, the need for heat application results in an additional process in the packaging.
A similar packaging method is disclosed in U.S. Pat. No. 4,757,900 where the heat-shrinkable inner packing element is fastened to the outer surfaces of the cardboard packing.
EP-A-0 686 577 discloses a method for preparing a plant package for transport and delivery, by which a number of floral containers in the form of pot means or vases are formed individually from sheet material such laminated polypropylene films and are subsequently at their bases connected to a support structure formed by the bottom of a box-shaped carton packing.
The object of the invention is to provide a method which in relation to the above known packing methods implies a substantial simplification and price reduction.
The method according to the invention is therefore characterized in that the adhesive layer is applied to a base surface portion of a plane foldable cardboard blank, that the product is placed on said portion, while the cardboard blank is in a plane condition and that subsequently the blank is folded up to form the cardboard packing.
Hereby, the need for production of a special inner packing adapted to the product is avoided, and the number of work operations both in packaging and unpacking are minimized.
The placement of the product directly on the plane cardboard blank prior to its folding-up makes the method according to the invention particularly usable for shock-resistant packing of products on an industrial scale as plane cardboard blanks with applied adhesive layer may for instance be conveyed automatically on a belt conveyor which at a packing station receives the products piece by piece.
Due to the proper stiffness of the box-shaped cardboard packing, both the protection of the packed products against mechanical impact and the possibility of a piled and organized placement of packed products during storage and transport are essentially equal to what can be obtained by the known packing methods, the retaining of the packed product to the adhesive layer on the base portion of the cardboard packing per se resulting in a secure localization of the product in the cardboard packing.
Moreover, by the folding-up of the parts of the cardboard blank surrounding the base surface, on which the product is placed, an air buffer zone is provided between the product and the walls of the finished box-shaped packing.
Advantageous embodiments of the method are stated in the dependant claims 2-9.
In a preferred implementation of the method, the product is completely wrapped with a barrier material prior to positioning on the adhesive layer. In particular, by use of an elastic barrier layer, such as a film material, a further improvement of the shock absorption provided due to deformability of the box-shaped packing and by the adhesive layer itself is obtained.
The invention further relates to a packing material for use in the method comprising a plane cardboard blank which is foldable to provide an essentially box-shaped cardboard packing, characterized in that an adhesive layer to be activated selectively is provided to a protion of the cardboard blank, which by folding of the blank into said cardboard packing will provide a base surface thereof.
By an adhesive layer to be activated selectively is here meant an adhesive layer which can beforehand be applied on the plane cardboard blank, but the adhesive properties of which are not activated until the method for packing of a product is carried out.
In a preferred embodiment of this plane cardboard blank, the applied adhesive layer comprises an outward adhesive tape covered by a removable protection layer.
The invention thereby offers the possibility of producing plane cardboard blanks an separate packing units for use both in connection with industrial packaging and in private households.